1. Field of the Invention
The present invention relates to a benzimidazolesulfonamide derivative or a salt thereof, and a pharmaceutical composition, particularly, an angiotensin II antagonist, containing said benzimidazolesulfonamide derivative or a pharmaceutically acceptable salt thereof.
2. Description of the Related Art
An angiotensin II is an octapeptide hormone having an activity to raise blood pressure. Increase of the hormone production causes hypertension or central nervous system diseases. Thus, it is known that inhibition of production or function of the angiotensin II is effective in the treatment for such diseases.
A renin inhibitor and an angiotensin converting enzyme (ACE) inhibitor which inhibit the production of the angiotensin II have been developed as an angiotensin II inhibitor. However, there are questions that these inhibitors cannot control the angiotensin II produced by enzymes other than renin and ACE, and that they affect other metabolic pathways.
The angiotensin II performs its function by the interaction with a particular receptor present in the cell membrane. Therefore, an antagonist of the angiotensin II receptor is greatly desired as an agent for inhibiting the action of all the produced angiotensin II at the receptor site without affecting other metabolic pathways, i.e., an agent which is more specific and hardly exhibits side effects.
As the angiotensin II receptor antagonist, for example, peptide analogues such as Saralasin were reported. However, its application is limited, because the antagonism thereof is not sufficient and does not have oral adsorbability. Non-peptide antagonists of the angiotensin II receptor were recently reported as an agent to remedy such defects. As an example thereof, 2-butyl-4-chloro-5-(hydroxymethyl)-1-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl] methyl]imidazole (DuP753: Du Pont) (J. Med. Chem., 34: 2525-2547, 1991) is known. However, compounds exhibiting the stronger angiotensin II antagonism have been desired increasingly.
Meanwhile, as benzimidazole derivatives, compounds described in Merck's EP Publication No. 400,835 [corresponding to Japanese Unexamined Patent Publication (Kokai) No. 3-27362], compounds described in EP Publication No. 392,317 [corresponding to Japanese Unexamined Patent Publication (Kokai) No. 3-63264: THOMAE K GmbH], and compounds described in Du Pont's U.S. Pat. No. 5,137,906 are known. However, the chemical structures of the above compounds are different from that of the benzimidazolesulfonic acid cyclic amide derivative of the present invention. It is believed that benzimidazole compounds are suitable, by virtue of pharmacological effects thereof, to treat diseases such as hypertension, heart failure, ischemic peripheral circulatory disorder, myocardial ischemia, diabetic nephropathy, glaucoma, and gastoenteropathy, and disease of urinary bladder, or prevent progression of heart failure after cardiac infarction.